I have 2 node setup using packstack icehouse installation using VXLAN tunnels. Below is my answer file:

[general]

# Path to a Public key to install on servers. If a usable key has not
# been installed on the remote servers the user will be prompted for a
# password and this key will be installed so the password will not be
# required again
CONFIG_SSH_KEY=

# Set to 'y' if you would like Packstack to install MariaDB
CONFIG_MARIADB_INSTALL=y

# Set to 'y' if you would like Packstack to install OpenStack Image
# Service (Glance)
CONFIG_GLANCE_INSTALL=y

# Set to 'y' if you would like Packstack to install OpenStack Block
# Storage (Cinder)
CONFIG_CINDER_INSTALL=y

# Set to 'y' if you would like Packstack to install OpenStack Compute
# (Nova)
CONFIG_NOVA_INSTALL=y

# Set to 'y' if you would like Packstack to install OpenStack
# Networking (Neutron). Otherwise Nova Network will be used.
CONFIG_NEUTRON_INSTALL=y

# Set to 'y' if you would like Packstack to install OpenStack
# Dashboard (Horizon)
CONFIG_HORIZON_INSTALL=y

# Set to 'y' if you would like Packstack to install OpenStack Object
# Storage (Swift)
CONFIG_SWIFT_INSTALL=n

# Set to 'y' if you would like Packstack to install OpenStack
# Metering (Ceilometer)
CONFIG_CEILOMETER_INSTALL=n

# Set to 'y' if you would like Packstack to install OpenStack
# Orchestration (Heat)
CONFIG_HEAT_INSTALL=n

# Set to 'y' if you would like Packstack to install the OpenStack
# Client packages. An admin "rc" file will also be installed
CONFIG_CLIENT_INSTALL=y

# Comma separated list of NTP servers. Leave plain if Packstack
# should not install ntpd on instances.
CONFIG_NTP_SERVERS=

# Set to 'y' if you would like Packstack to install Nagios to monitor
# OpenStack hosts
CONFIG_NAGIOS_INSTALL=n

# Comma separated list of servers to be excluded from installation in
# case you are running Packstack the second time with the same answer
# file and don't want Packstack to touch these servers. Leave plain if
# you don't need to exclude any server.
EXCLUDE_SERVERS=

# Set to 'y' if you want to run OpenStack services in debug mode.
# Otherwise set to 'n'.
CONFIG_DEBUG_MODE=n

# The IP address of the server on which to install OpenStack services
# specific to controller role such as API servers, Horizon, etc.
CONFIG_CONTROLLER_HOST=10.100.1.26

# The list of IP addresses of the server on which to install the Nova
# compute service
CONFIG_COMPUTE_HOSTS=10.100.1.32

# The list of IP addresses of the server on which to install the
# network service such as Nova network or Neutron
CONFIG_NETWORK_HOSTS=10.100.1.26

# Set to 'y' if you want to use VMware vCenter as hypervisor and
# storage. Otherwise set to 'n'.
CONFIG_VMWARE_BACKEND=n

# Set to 'y' if you want to use unsupported parameters. This should
# be used only if you know what you are doing.Issues caused by using
# unsupported options won't be fixed before next major release.
CONFIG_UNSUPPORTED=n

# The IP address of the VMware vCenter server
CONFIG_VCENTER_HOST=10.100.1.26

# The username to authenticate to VMware vCenter server
CONFIG_VCENTER_USER=

# The password to authenticate to VMware vCenter server
CONFIG_VCENTER_PASSWORD=

# The name of the vCenter cluster
CONFIG_VCENTER_CLUSTER_NAME=

# (Unsupported!) The IP address ...